Coherent noise reduction in digital holographic microscopy by laterally shifting camera

Abstract

The inherited coherent noise degrades the imaging quality and resolution in digital holographic microscopy. A method to reduce coherent noise is proposed in this paper. Firstly, a series of digital holograms are recorded by laterally shifting camera. Secondly, the different holograms are reconstructed individually, and the additional lateral displacement and phase shift of the reconstructed images due to the change of camera position are corrected by using the phase compensation and image registration algorithms. Thus, multiple identical retrieved images of object are obtained with different coherent noise distributions. Finally, a reduction of coherent noise is achieved by a proper averaging process for amplitude and phase image. The feasibility of this method is demonstrated by imaging of the resolution targets and the red blood sample.